A. Field of Invention
This invention relates generally to the field of crossbows and, more specifically, to apparatuses and methods regarding changing the draw weight of a crossbow.
B. Description of the Related Art
Crossbows have been used for many years as a weapon for hunting, fishing, and for target shooting. In general, a crossbow includes a main beam including a stock member and a barrel connected to the stock member. The barrel typically has an arrow receiving area for receiving the arrow that is to be shot. The crossbow also includes a bow assembly supported on the main beam that includes a bow and a bowstring connected to the bow for use in shooting arrows. A trigger mechanism, also supported on the main beam, holds the bowstring in a drawn or cocked condition and can thereafter be operated to release the bowstring out of the drawn condition to shoot the arrow.
One way to rate crossbows is by their draw weight, which is the amount of force require to draw or pull the bowstring into the cocked condition. The draw weight of a crossbow is a major factor in determining the speed at which the arrow will be fired. As a general rule, the greater the draw weight, the faster the arrow will travel. Known crossbow draw weights vary considerably, from 50 pounds (LBS) to 200 LBS, for example. This produces an equally varying range of initial arrow speeds, from 130 feet per second (FPS) to 350 FPS, for example.
While known crossbows having distinct draw weights generally work well for their intended purpose, they have an important disadvantage. This disadvantage is based on the fact that the desired draw weight for a particular use may vary. Hunters, for example, may desire a relatively larger draw weight to provide a flatter trajectory and thus improved firing accuracy.
The particular atmospheric conditions may also require varying crossbow draw weights. Hunting or target practice in fog, rain, snow or strong winds, for example, may require faster arrow speeds. When the atmospheric conditions are relatively mild, however, hunting or target practice may be accomplished using a slower arrow speed.
The desired draw weight for a crossbow may also vary based on the user. It may be desirable, for example, to start a young and/or inexperienced user with a smaller draw weight crossbow and then, as the user gains in experience and skill, provide a larger draw weight. Some other user characteristics that may variably affect the desired crossbow draw weight include advancing age, health, injury, flexibility, eyesight, disability, and the like.
The conventional solution to this need for varying crossbow draw weights is to provide multiple crossbows—each having a distinct and specific draw weight. The use of multiple crossbows, however, has the disadvantage of increased expense to purchase multiple crossbows. The use of multiple crossbows also has the disadvantage of inconvenience because the user must now transport the numerous crossbows to the point of use and switch between them, as needed.
The crossbow of this invention can be easily adjusted to provide multiple draw weights. In this way the disadvantages known in the art can be overcome in a way that is better, more efficient and that provides better overall results.